There is currently some ambiguity in our documentation around positional and keyword arguments (e.g. whether positional means "position-only" or "non-keyword" (roughly) and whether various terms and definitions should be for the calling syntax or the function definition syntax or both).  For example, see the python-dev thread starting here:

http://mail.python.org/pipermail/python-dev/2012-September/121760.html

It would be good to nail down the preferred terminology in a central place.  I would suggest that the glossary is a good place to start.

For example, when there is a question about what phrase an error message should use or how an error message should be interpreted, it would be good if (at least going forward) the glossary could be used as a definitive resource.

This issue may involve making a distinction in our terminology "between arguments (what you pass, call syntax) and parameters (what the function receives, function definition syntax)" (see http://mail.python.org/pipermail/python-dev/2012-September/121771.html ).